Crawford would hardly be the last impactful injury during the first 10 days of camp around the league, however.

Fate turned on Eagles coach Chip Kelly just two days into his first training camp as an NFL mentor when arguably his best receiver, fifth-year veteran Jeremy Maclin, went down with a torn ACL in his right knee on Saturday.

Maclin was carted off after suffering a non-contact injury during 7-on-7 drills. The University of Missouri product laid on the ground in pain for several minutes as concerned teammates made their way over to check on him.

Kelly and another assistant helped Maclin to his feet but it was clear that the receiver was favoring his right leg quite a bit. As the cart drove Maclin off the field, the fans assembled cheered but Maclin seemed terribly dejected and draped a towel over his face.

"I saw it out of the corner of my eye," quarterback Michael Vick said following the practice. "I saw him fall. And usually when a guy falls like that, it's something to be worried about. But hopefully everything will work out."

It didn't -- the Eagles confirmed Maclin tore the ACL in his right knee hours later and Maclin himself addressed the issue on his Twitter account.

"Appreciate all the love and support twitter fam....sad day but I have setbacks my entire life. Minor setback for a MAJOR comeback!" Maclin Tweeted.

That same day about 110 miles south in Owings Mills, MD, Ravens tight end Dennis Pitta suffered a season-ending dislocated hip injury after colliding with safety James Ihedigbo during a jump ball situation.

"Asking for prayers for a speedy recovery and heal time as I go through this ordeal," Pitta wrote on Facebook.

The next day it was the Denver Broncos turn to handle adversity as veteran center Dan Koppen was carted off with a torn anterior cruciate ligament of his own.

"I always cringe," Broncos coach John Fox said when asked about seeing players get hurt. "You never like to see players get injured, particularly severely injured. But you understand when you do this long enough, whether you're a player or a coach, that this happens."

On Monday the Chicago Bears watched defensive lineman Turk McBride succumb to a ruptured Achilles hours before the Eagles were slammed yet again when linebacker Jason Phillips, a special teams stalwart, suffered the same injury as Maclin two days earlier, a torn ACL in his right knee.

Overcoming misfortune is essential for any NFL team and the league-wide motto might as well be "next man up," the most popular refrain when league executives talk about injury.

"It's sadness," Kelly said when asked about injuries. "When you get back, the reality of it is you got to get ready with the guys that are able to play and healthy to play. It's kind of like someone dropped their shield in battle and the other guy has to pick it up, pick up the slack for him."

The mind-numbing series of early season-enders brings to the forefront the new practice rules since the implementation of the new Collective Bargaining Agreement before the 2011 regular season.

There is much less contact in today's NFL practice landscape and teams are under stringent offseason restrictions regarding seemingly simple things like press coverage.

Kelly, for one, allows no tackling to the ground at any of his practices.

"No, we have four preseason games for that." the former University of Oregon coach said Monday when a reporter asked if the Eagles would be tackling at all during practice sessions. "They're hitting pretty good when they get an opportunity. The big thing with tackling, you want to be on your feet anyway. We don't want people diving. We want to be good form tackle so they get an opportunity. In the first team period we do every day, we're going to be doing that."

The thought process behind Kelly's no tackling-manta is limiting injuries, something which obviously takes a hit considering he has already lost two players to ACL tears without any violent collisions.

"When you get guys on the ground, it is not really the two guys that get tackled, it's what's chasing it," Kelly explained. "We're trying to keep everybody in every situation up. You have a lot of big bodies moving. There's a fine line what we have to get done from a work standpoint. We also know we have to get our guys to the game, too."

"I know Chip Kelly is probably going to get killed but I'm not sure the same thing doesn't happen if Andy Reid was still the coach (in Philadelphia)," Dr. David Geier, one of the top orthopedic surgeons in sports who once assisted in the care of the St. Louis Rams, said. "Most of these (injuries around the league) have been non-contact so there is not much you can do."

That said, more than one coach has privately questioned whether things like the lack of contact or the scaled-down offseason programs are having an affect on things.

Players arrive at camp these days after a six- or seven-week respite for two mandatory practices with no pads before finally being asked to ramp things up. Some think that could be like jumping into an ice cold shower, a shock to the system in what remains a terribly physical game built upon violent contact.

"Time away can play a role," Geier explained. "It's a possibility it could be a cause but I think for different reasons than a coach might think. It's not like these guys are sitting around on couches for weeks but the one thing you can't replicate is the repetition during team activities. The ability to run, cut and plant your foot with a defender there."

"All those repetitions are functional movements and they are hard to replicate without the spontaneity of movement," he continued. "It's a muscle memory thing and that's why you usually see a spike of these types of injuries in the first seven to 10 days (of camp)."

Others argue certain players work out far too much and their tendons, joints and muscles are ticking time bombs when they finally hit the field.

"We think there is something to that," Geier said when asked about overdoing it, "but it's hard to say there is a direct cause and effect. Jerry Rice was famous for his work ethic and he stayed healthy for the vast majority of his career."

So is there a way to prevent these kinds of injuries or at the very least scale them back?

"Yes and no," Geier said. "It's hard to say any rule change is going to make a difference but the U.S. Women's Soccer team implemented a program which teaches landing mechanics when turning and pivoting in the air. That type of thing could be very helpful."